1. Field of the Invention:
This invention relates to paper roll handling apparatus used in a commercial printing operation and in particular it relates to an apparatus for transferring support shafts from the cores of used-up paper rolls to replacement paper rolls.
2. Background of the Invention:
Paper utilized in commercial printing processes for printing, e.g. computer paper forms is supplied in large heavy rolls, e.g. of several thousand pounds. The rolls have a center core into which expandable shafts are insertable. The shafts facilitate the handling, moving and transferring of the paper rolls into the paper feed mechanism of a printing press.
The shafts that are utilized are of the expandable type. The shafts are inserted into a center core of the paper roll and are expanded, generally by the application of air pressure. The shafts have fingers or lobes that are extendable when air pressure is applied to engage the internal diameter of the roll core. The shafts extend beyond the ends of the roll. A hoist engages the ends of the shaft protruding from the ends of the roll to transport the roll to the in-feed section of the printing press. The ends of the shaft are supported in journals at the in-feed section of the press. When the paper on the roll has been depleted, that is fed into the printing press, the assembly of the shaft and the core remaining is transferred by the hoist out of the in-feed section of the press.
Until now, the assembly of the shaft and remaining core was manually removed from the hoist. The assembly was generally carried to a support fixture where the applied air pressure was released and the core of the paper roll was manually removed from the shaft.
One of the problems encountered was the weight of the assembly (i.e., the shaft and attached core). It weighs in the vicinity of 110 to 120 pounds. It was found that injuries occurred from the manual handling of the shaft and core.
Another problem encountered was the removal of the core from the shaft. In many instances, the fingers or lobes of the shaft would have dug into the core material. The core material of the roll is of paper construction (e.g. cardboard) and the extended fingers or lobes would penetrate the core material. This generally happened when a braking was applied to the roll and the shaft would tend to rotate relative to the roll and the fingers or lobes would "dig" in to the core. When this occurred, it was very difficult to remove the core from the shaft. In many cases, the core would have to be cut off.
When the core was finally removed from the shaft, the shaft was then manually inserted into a new roll. This required the manual lifting of the shaft off of the holding fixture, carrying the shaft to the location of a new roll and inserting the shaft into the core of the new roll.